Improvement of environmental performance

Sea transport generates emissions to the sensitive marine environment. A significant part is emission from engine exhaust gases.

In October 2008 the International Maritime Organization (IMO) adopted a set of amendments to Annex VI of the MARPOL Convention. One of these is about limitation of sulphur (0.1 %) in fuel used in Sulphur Emission Control Areas (e.g. English Channel, North Sea and Baltic Sea). The emission of SOx is expected to be considerably reduced in the Baltic Sea Area when the new rules are in force 1 January 2015.

Technical solutions for reduction of NOx on-board ships have developed in the recent years, both the after-treatments of exhaust gases and the combustion technics. The Swedish Maritime Administration’s buoy-tender Scandica and icebreaker ATLE where among the first vessels where after-treatment equipment was installed. Experiences from these two installations were important for further development of this cleaning technique. This Activity aims to contribute to reduction of Black Carbon, NOx and CO2 by development of combustion technic by new fuel injection technique on existing engines.

The Finnish and Swedish icebreakers of ATLE/URHO class were built in the seventies but are still in very good condition. The propulsion systems are DC diesel-electric, where 10 generators are fitted on five 3680 kW Pielstick (12PC2-2V ATLE) engines on board each vessel.

Existing fuel injection systems are traditional which results in combustion that is not optimized. Suitable fuel injection systems for retrofit of existing diesel engines in order to reduce emissions are not available on today’s market and can thus not be purchased.

The project aim is to perform a full scale pilot project where new fuel injection technique will be tested on board an icebreaker. The expected result is less fuel consumption and emissions, particularly Black Carbon (particles), NOx and CO2.

An icebreaker is convenient for this kind of project due to the sufficient time for installation works during the ice free season. A diesel-electric propulsion system is suitable for the test due to the possibility to easily measure used power and compare with fuel consumption and emissions during different loads.

The outcome of the pilot project will be the basis for decisions if other vessels shall be upgraded with this kind of new technical system.

The Activity is subdivided in five sub activities according the descriptions below.

Sub activity 3:1.

A technical pre-study has been performed in order to map the technical characteristics and identify measures and technical works which are required for drafting of the project plan.

Sub activity 3:2.

The components and the software has been designed and adapted to the engines and the existing engine monitoring and control systems. Required drawings and other technical specifications for manufacturing have been worked out.

Sub activity 3:3.

Manufacturing of prototype’s components, system software and installation aboard have been performed. Start test and preliminary adjustments have been done.

Sub activity 3:4.

First measures and tests on the prototype engine have been carried out. Some modifications are needed and new test performed in the near future. Functionality test, measures of emissions and fuel consumption will be the main spots for tests and measures. Possible adjustments of components and software will be performed as well.

The new engine parts have been designed, manufactured and fitted on one of the five main engines aboard icebreaker YMER.  Test trails during icebreaking operations have been carried out during the icebreaking season.  The first results were promising but more adjustments and trimming was required in order to find the optimal setting.

The first engine, fitted with the new fuel injection system has been in service during the ice season with satisfying results regarding reduction of fuel consumption and “black carbon” emission. There have been some difficulties with leakage from high pressure pipes. Pipes with a new design are manufactured, mounted and tested with satisfactory result.

The level of NOx emission did not meet the goal at first. In order to reduce the NOx emission, the system was fitted with an Exhaust Gas Recycling (EGR) function. Tests trails with water injection technique were performed during ice season 2015. The latest tests with new, lighter and up to date designed turbocharger have been performed. The results showed significant reduction of NOx emission to an acceptable level and maintained reduction of fuel consumption (6-7%).

Sub activity 3:5.

All engines of the vessel could not be fitted with the new fuel injection equipment during the project time. Tests with one fitted engine have been performed. The work to fit all the remaining engines continutes with further development.